A：输出到各自文件夹

convert.py

@@ -1,8 +1,8 @@
 """
 Convert all music under E:\\Music (except E:\\Music\\工具) to AAC (.m4a) using ffmpeg.
-Outputs are written flat into E:\\Music\\工具\\TypeChange\\out; if two source files
-or existing outputs share the same name, the last one wins and a summary of
-overwrites is printed at the end.
+Outputs are written under E:\\Music\\工具\\TypeChange\\out mirroring the folder
+structure under SOURCE_ROOT; if two source files map to the same target path,
+the last one wins and a summary of overwrites is printed at the end.
 
 Notes:
 - If the source is already `.m4a`, it is copied as-is by default (no re-encode).
@@ -20,7 +20,7 @@ from pathlib import Path
 from concurrent.futures import ThreadPoolExecutor, as_completed
 
 # Source and destination roots
-SOURCE_ROOT = Path(r"E:\Music")
+SOURCE_ROOT = Path(r"E:\Music\完成\专辑")
 SKIP_ROOT = SOURCE_ROOT / "工具"
 OUT_ROOT = Path(r"E:\Music\工具\TypeChange\out")
 
@@ -108,8 +108,15 @@ def iter_source_files():
 
 
 def build_output_path(src: Path) -> Path:
-    """Place all outputs in OUT_ROOT, using only the filename with .m4a extension."""
-    return OUT_ROOT / src.with_suffix(".m4a").name
+    """Mirror SOURCE_ROOT folder structure under OUT_ROOT, changing extension to .m4a."""
+    try:
+        relative = src.relative_to(SOURCE_ROOT)
+    except ValueError:
+        try:
+            relative = src.resolve().relative_to(SOURCE_ROOT.resolve())
+        except (OSError, RuntimeError, ValueError):
+            relative = Path(src.name)
+    return OUT_ROOT / relative.with_suffix(".m4a")
 
 
 def find_external_cover_image(src: Path) -> Path | None: